Mask filter



FIG. 1 is a front elevation view of a first embodiment of a mask filter;

FIG. 2 is a rear elevation view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a bottom plan view thereof;

FIG. 5 is a right side elevation view thereof;

FIG. 6 is a left side elevation view thereof;

FIG. 7 is a top, front, right perspective view thereof;

FIG. 8 is a plan view of the mask filter of FIG. 1 , shown in a folded configuration for clarity of disclosure;

FIG. 9 is a cross-sectional right side elevation view thereof, taken along line 9-9 of FIG. 8 ;

FIG. 10 is an enlarged detail view of the portion of FIG. 9 taken along line 10′-10, shown in perspective; and

FIG. 11 is a top, front, right perspective view of the first embodiment of the mask filter in condition of use.

FIG. 12 is a front elevation view of a second embodiment of a mask filter;

FIG. 13 is a rear elevation view thereof;

FIG. 14 is a top plan view thereof;

FIG. 15 is a bottom plan view thereof;

FIG. 16 is a right side elevation view thereof;

FIG. 17 is a left side elevation view thereof;

FIG. 18 is a top, front, right perspective view thereof;

FIG. 19 is a top plan view of the mask filter of FIG. 12 , shown in a folded configuration for clarity of disclosure;

FIG. 20 is a cross-sectional right side elevation view thereof, taken along line 20-20 of FIG. 19 ;

FIG. 21 is an enlarged detail view of the portion of FIG. 20 taken along line 21′-21, shown in perspective; and,

FIG. 22 is a top, right, front view of the second embodiment of the mask filter in condition of use.

In the drawings, the dotted lines depict unclaimed portions of the mask filter that form no part of the claimed design. The dash-dot-dash broken lines define the boundaries of the claim. The equal-length broken lines in FIG. 11 and FIG. 22 , showing a human head and shoulders, depict environmental structure only and form no part of the claimed design. All broken and dotted lines form no part of the claim. 

CLAIM The ornamental design for a mask filter, as shown and described. 